diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2024-03-02 00:45:14 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-03 00:06:20 +0300 |
| commit | 2432f71c22d0543a86353ed0c505eda32d25af7c (patch) | |
| tree | f5e407b4953fda2479b637e6a77c28a6b06cdec3 /drivers/tty | |
| parent | 65295eba1915cf27c363f26727f6da43d144d03b (diff) | |
| download | linux-2432f71c22d0543a86353ed0c505eda32d25af7c.tar.xz | |
serial: amba-pl011: Use uart_prepare_sysrq_char().
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Delay handling sysrq until port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-2-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 24 |
1 files changed, 8 insertions, 16 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index cf2c890a560f..2fa3fb30dc6c 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -348,10 +348,7 @@ static int pl011_fifo_to_tty(struct uart_amba_port *uap) flag = TTY_FRAME; } - uart_port_unlock(&uap->port); - sysrq = uart_handle_sysrq_char(&uap->port, ch & 255); - uart_port_lock(&uap->port); - + sysrq = uart_prepare_sysrq_char(&uap->port, ch & 255); if (!sysrq) uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); } @@ -1017,7 +1014,7 @@ static void pl011_dma_rx_callback(void *data) ret = pl011_dma_rx_trigger_dma(uap); pl011_dma_rx_chars(uap, pending, lastbuf, false); - uart_port_unlock_irq(&uap->port); + uart_unlock_and_check_sysrq(&uap->port); /* * Do this check after we picked the DMA chars so we don't * get some IRQ immediately from RX. @@ -1540,11 +1537,10 @@ static void check_apply_cts_event_workaround(struct uart_amba_port *uap) static irqreturn_t pl011_int(int irq, void *dev_id) { struct uart_amba_port *uap = dev_id; - unsigned long flags; unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; int handled = 0; - uart_port_lock_irqsave(&uap->port, &flags); + uart_port_lock(&uap->port); status = pl011_read(uap, REG_RIS) & uap->im; if (status) { do { @@ -1573,7 +1569,7 @@ static irqreturn_t pl011_int(int irq, void *dev_id) handled = 1; } - uart_port_unlock_irqrestore(&uap->port, flags); + uart_unlock_and_check_sysrq(&uap->port); return IRQ_RETVAL(handled); } @@ -2322,13 +2318,10 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) clk_enable(uap->clk); - local_irq_save(flags); - if (uap->port.sysrq) - locked = 0; - else if (oops_in_progress) - locked = uart_port_trylock(&uap->port); + if (oops_in_progress) + locked = uart_port_trylock_irqsave(&uap->port, &flags); else - uart_port_lock(&uap->port); + uart_port_lock_irqsave(&uap->port, &flags); /* * First save the CR then disable the interrupts @@ -2354,8 +2347,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) pl011_write(old_cr, uap, REG_CR); if (locked) - uart_port_unlock(&uap->port); - local_irq_restore(flags); + uart_port_unlock_irqrestore(&uap->port, flags); clk_disable(uap->clk); } |